Hurricane Harvey formed in the open Atlantic Ocean, but was a weak tropical cyclone until it entered the Bay of Campeche. Once in this bay, it rapidly intensified to a Category 4 hurricane and moved toward Texas, eventually flooding much of Houston. Houston was not placed under mandatory evacuation for several reasons. One of those reasons was logistical – evacuating 7 million people is a logistical nightmare. Let’s see how long it would take to evacuate the Houston metro area if everything ran smoothly (i. e., people were prepared and there were no accidents blocking roads, etc.). Required:
Using the information below, calculate how long (in days) it would take to evacuate all 7 million people from the Houston metro area.

Assumptions:

Assume all the people evacuate by car and that each car carries an average of 2.3 people
Assume that all cars evacuate using major roadways (Interstates, expressways, highways) and that there are a total of 48 outbound lanes leaving the Houston metro area
The rate of cars exiting the metro area is 1 car per 3.9 seconds per lane.